Conventionally, aircraft fuselages, main wings, and the like are manufactured using completely cured prepreg layered bodies. The completely cured prepreg layered bodies are each formed by layering a plurality of prepreg sheets (FRP sheets), each of the prepreg sheets being formed of a fiber sheet impregnated with resin, to form a semi-cured (incompletely cured) prepreg layered body and then completely curing the semi-cured prepreg layered body.
The fibers forming the fiber sheet described above extend in the same fiber direction. In addition, the fiber sheet has adhesiveness because an ultraviolet curable resin, a thermosetting resin, or the like in a semi-cured state (incompletely cured state) is used as the resin with which the fiber sheet is impregnated. For this reason, a release sheet is arranged on one surface of the prepreg sheet.
The prepreg layered body in the semi-cured state described above is formed using a device for automatically layering prepreg sheets. Specifically, the device for automatically layering prepreg sheets forms a semi-cured prepreg layered body by removing the release sheet from the semi-cured prepreg sheet and integrally layering a plurality of the prepreg sheets while the fiber directions of the fiber sheets are made to intersect each other.
At this time, if air (air pockets) remains between the layered, semi-cured prepreg sheets, the adhesion between the prepreg sheets may decrease.
In addition, when the above-described semi-cured prepreg layered bodies in which the air remains are completely cured, for example, using heat (in this case, the resin forming the prepreg sheet is a thermosetting resin), the air (the air pockets) expands, which could lead to a further decrease in the adhesion between the prepreg sheets.
Therefore, conventionally, air (air pockets) is prevented from remaining between layered, semi-cured prepreg sheets by press-bonding the semi-cured prepreg sheets using a compactor (one of the constituent components of the device for automatically layering prepreg sheets) including a piston mechanism.
However, if the release sheet is insufficiently peeled off from the semi-cured prepreg sheet, the semi-cured prepreg sheets may be pulled by the release sheet such that the prepreg layered body (in other words, a layered body formed of one or more semi-cured prepreg sheets), which is in a semi-cured state under manufacturing floats up, or such that the position of the layered body is shifted from a predetermined position.
In addition, in a case of using a compactor including a piston mechanism, when there is a layered surface in which the crimping between the semi-cured prepreg sheets is insufficient, there is a possibility that the position of the above-described semi-cured prepreg layered body (layered body) during the manufacturing will be shifted from a predetermined position due to the translational driving force of the compactor.
Conventionally, in a case where the semi-cured prepreg layered body (layered body) is misaligned under manufacturing, the prepreg layered body (layered body) which has been misaligned under manufacturing is removed manually and the semi-cured prepreg sheet layering process is performed again. For this reason, the productivity of the semi-cured prepreg layered body is decreased.
For this reason, there is a demand for a technique which, by facilitating the peeling off of the release sheet from the semi-cured prepreg sheet, can suppress the misalignment of the semi-cured prepreg layered body (layered body) under manufacturing and improve the adhesion between the layered, semi-cured prepreg sheets.
For example, Patent Document 1 describes a conventional technique which can improve the adhesion between the semi-cured prepreg sheets.
Patent Document 1 discloses a technique in which a prepreg material (prepreg sheet) is fed and taken out from a cartridge, the tackiness (adhesiveness) is improved by heating through contact with a heated compaction roller, and the prepreg material is pressed and layered on a forming jig by the compaction roller.